<!DOCTYPE HTML>
<html>
<body>
<style>
body {
  padding: 100px;
  width: 5000px;
  height: 5000px;
  overflow: scroll;
}
div {
}
#parent {
  background:red;
  width: 64px;
  height: 64px;
}
#child {
  background:green;
  position:fixed;
  width: 32px;
  height: 32px;
}
</style>
<div id="parent">
<div id="child">

</div>
</div>
<script type="application/javascript">

if (document.location.search == '?willchange') {
  document.getElementById("parent").style.willChange = "transform";
} else if (document.location.search == '?ref') {
  document.getElementById("parent").style.transform = "translateZ(1px)";
} else if (document.location.search == '?noblock') {
}

document.documentElement.scrollTop = 10;
document.documentElement.scrollLeft = 10;
</script>
</body>
</html>
